Algo(T,k1,k2)
P = NIL
Z = T
Y,X;
	while (z!= NIL) do
		P=Z
		If Z->key < k1 then
			Z=Z->dx
		If Z->key > k2 then
			Z=Z->sx
		else
			If (Z->sx == NIL OR Z->dx == NIL) Then
				Y=Z
		else
			Y=Z->dx; P=Z
			while(Y->sx != NIL) DO
				P=Y
				Y=Y->sx
		If (Y->sx != NIL) then
			X=Y->sx
		else
			X=Y->dx
		If (P=NIL) then
			T=X
		else if (Y=P->SX) then
			 P->sx = X
		      else
			 P->dx = X
		If (Y!=Z) Then
			"copia i campi di y in z"
		"dealloca Y"
	return T